Exhaust gas purifying catalysts used for cleaning the exhaust of internal combustion engines and the like are required to have a very high heat resistance in order to keep a high catalytic activity even when used at a high temperature for a long period.
Known as an example of exhaust gas purifying catalysts is one in which a metal having a catalytic activity is supported on a carrier made of a particulate metal oxide. For enhancing the heat resistance of such an exhaust gas purifying catalyst, one using a carrier in which an oxide of a rare-earth element is uniformly dissolved as a solid in zirconium oxide particles (Japanese Patent Publication No. 3498453) and one using a carrier in which aluminum oxide and an oxide of a rare-earth element are combined with each other (Japanese Patent Publication No. 3275356) have been proposed so far.